Thermo-sensitive pump



Aug. 5, 1958 Filed April 25, 1955 E. J. HERBENAR 2,845,869

THERMO-SENSITIVE PUMP 2 Sheets-Sheet 1 Lrazzfmr 1958 E. J. HERBENAR 2,845,869

THERMQ-SENSITIVE PUMP Filed April 25, 1955 2 Sheets-Sheet 2 EYE 2221b? Eda/am c]. Herbezzar United States Patent A; if

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THERMO-SENSITIVE PUMP Edward J. Herbenar, Detroit, Mich., assignor to Thompson Products, Inc., Cleveland, Ohio, a corporation of Ohio Application April 25, 1955, Serial No. 503,630

Claims. (Cl. 103-97) This invention relates to pumps having pumpingrates' varying'automatically in response to the temperature of fluid being'pumped.

Specifically, this invention" deals with a pump rotor or impeller with thermosensitive pumping elements which change position in response to temperature changes to increase'or decrease the flow rate through the pump.

In its preferred forms the rotor or'impeller has a slotted peripheral-wall in communication with the inlet and outlet of the pump. Thermo-sensitive bi-metal pumping vanes control flow through the slots and shift position to vary theirfl'uid' displacing capacity. When the bi meta'llic'members are in an open-position they project" from the rotor to" form pumping vanes. When in a closed position the bi-metallic members hug the impeller wall close the slots so that rotation of the impeller'will not create a propelling of "fluid'and will block flow Between the pump inlet and outlet. Between fully opened and fully closed positions the bi-metal' members may assume intermediatepositions to provide intermediate pumping, rates for thepump.

While the bi-metal elements are preferably arranged to increase their pumping rates as they increase in temperatur'e; a reversed arrangement can be provided, if desired, without departing from this invention, whereby the'pumpi'ng rate" will increase upon a decrease intemperature.

Accordingly; a feature of this invention is to provide a thermo-sensitive pumpwhich automatically varies its pumping rate in accordance with the temperature of its pumping elements.

It is also an object of this invention to provide an inexpensive thermo-sensitive pump;

A further object of theinvention is the provision of a thermo-sensitive fluid impeller which has a variable pumping rate controlled by its" temperature.

A further object is to provide a centrifugal pump with bi-metal vanes which shift in response to temperature changes for'varyingthe pumping rate.

Another object of the invention is to provide a pump impeller with a slotted peripheral wall carrying bi-metal elements to control flow through the slots and to project from the wall' to form pumping vanes.

Still" another object of this invention is to provide a thermo-se'nsitive coolant pump for an automobile engine or the like'which automatically controls flow of coolant through the engine circulating system in response to coolant temperature; thereby avoiding the necessity for a thermostat valve.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of examples only, illustrate two embodimentsof theinvention.

The drawings:

Figure 1 is a fragmentary cross sectional view with parts in elevation of a centrifugal fluid pump embodying f'eatu'res'of the present invention;

2,845,869 Patented Aug. 5, 1958 Figure.2 is a cross sectional view taken on the line lI-II of Figure 1 further illustrating features; of my novel fluid pump construction;

Figure3 is a fragmentary cross sectional view similar to Figure 1 but. showing a modified impeller construction;

Figure 4 is a fragmentary cross sectional view taken on the line IV-IV of Figure 3 further illustrating my novel modified impeller construction; and

Figure 5 is a side elevational, view of my modified impeller construction.

As shown on the. drawings:

The numeral 10 indicates generally my. novelcentrifu: gal fluid pump assembly whichmay be usedlwith. anv automobile or the like and when used preventsv the circur lation of fluid until the fluid. reaches a. predetermined temperature.

The pump 10 has a casing 11 defining a chamber or housing 12 havinga fluid inlet 13 and outlet 14. Extending into the casing 11 is a drive shaft 15 which has a suitable shaftbearing assembly 16 for carrying same. Suitably securedto one end of the drive shaft 15 is a hub 17 which is in turn suitably secured at 18 to a pulley 19. The pulley 19 is suitably adapted to be belt driven by a prime mover (not shown).

Suitably secured to the other end of the drive shaft 15 is a second'hub 20 which carries a suitable shaft. seal 21 and a second seal 22 bearing upon flange 23 of casing 11.

Suitably carried on the terminal end of drive shaft 15 adjacent hub 20 is a cup-shaped disk or rotatable impeller 24 which is, carried within. housing 12 of the centrifugal pump 10.

The cup-shaped disk or impeller 24 includes a main generally radially extending annular section 25 with agenerally axially extending annular flange 26 on the terminal end of radial section 25. The annular flange 26 has a pluralityof circumferentially spaced slots 27 defining con: necting channels between the fluid inlet 13 and outlet 14 for receiving therethrough fluid. Suitably secured by a rivet or the like on the inlet or downstream side of the slot- 27 and extending over to close same is a laminated heat responsive bi-metallic element 28.

The bi-metallic element 28wmay be made of any suitable metals or the like having different coefficients of expansion such as copper and steel with the lamination 2821 in closest proximity to the slot 27 suitably of a higher coefficient of expansion than the outer lamination 28b= since the desired curling. action seen in Figure 2 is in that manner most readilyobtainable.

In other words, as the heat of fluid heats the bimetallic element 28 the lamination 28a having a higher co'efiicient of expansion expands to a greater extent than the lamination 2812 which has a lower coefiicient of expansion. It isin this manner that the curling of the element 28 is effected to open the slot 27 thereby permitting fluidto be pumped therethrough. The channels or slots 27 remain closed until the temperature of the fluid to be pumped reaches a predetermined temperature at which time the bi-metallic elements become curled as'shown by the dotted lines in Figure 2.

Formed with or mounted on section 25 is an annular shouldered abutment or protuberance 29 defining a stop which is located in a predetermined position relative to the respective slots 27. Upon the curling of the bimetallic elements 28 the respective ends 30 of the same are biased inabutting relation against the stop 29 (Fig. 1). By providinga stop 29 againstwhich the ends 30 of the elements 218 may be shouldered the deformation of the elements 28 may becontrolled; his in this manner that the elements 28 may also be utilized as vanes for facilitating in the directing of fluid into the respective channels 27. It has been found that by shoulderifig' the vanes or bi-metallic elements 28 as above described, that the high speed action-f-the driven cup shaped disk or impeller 24 against thefiuid in the housing reduces any propensities of the fluid to so deform the elements 28 that they may not be used as vanes.

As the engine warms up the fluid in the circulating system will reach a given predetermined temperature at which time the heat responsive bi'metallic elements 28 will expand and curl against the annular shoulder 29 on the rotating impeller 24 and thereafter serve in the capacity of vanes to facilitate directing the centrifugally impellzesd fluid out through the slots 27 into the pump outlet Figures 3, 4, and illustrate amodified impeller pum construction indicated generally at 32. It will be appreciated that the pump 32 operates in the same manner as the pump shown in Figures 1 and 2 and that the pump 10 is structurally identical with pump 32 excepting the modified impeller constructionwhich will be hereinafter discussed in detail. Where identical elements have been employed in pump-32 as in pump 10 the same numerals have been used. I

The impeller 31 includes a main generally radially extending annular section 33 with a generally axially extending annular flange 34 on the terminal end of radial section 33. The annular flange 34 may be made of a metal which has a relatively low coefficient of expansion.

About the circumference of the I generally axially extending flange 34 are a plurality of deformable integral cutouts or strips or tabs 35 which have been punched from the flange 34 and deformed inwardly to form openings or slots 36 which define channels communicat- I ing the inlet 13 with the outlet of the pump 32.

After the flange 34 has been punched to form a plurahty of tabs 35 a strip of material having a relatively high coeflicient of expansion such as copper, correspondmg in size to the size of the opening or slot 36 is suitably secured to the inner surface of the tab 35. In other words, the copper strip 37 may be welded to the inner surface of the steel or the like tab 35.

In the operation of the pump the tab functions in the same manner as described in connection with the first form of my invention. The tab responds to changes in the fluid temperature and when sufliciently heated the end 38 of the tab progressively curls and eventually is biased against the inner annular shoulder or stop 39. It is in this manner that the slots 36 defining channels communicating the inlet and outlet are opened and closed. After the tabs 35 have sufliciently deformed to open the slots 36 the tabs then serve as vanes to facilitate in directing the centrifugally moving fluid through the slots or channels 36.

From the above description it will therefore be understood that fluid from the inlets 13 of the pumps of this invention flows through the eyes of the pumps into the pump impellers Where it is surrounded by the annular impeller peripheries 25 or 34. When the fluid is at an elevated temperature the bi-metal elements 28 or 35 will be curled inwardly from the impeller peripheries to form centrifugal pumping vanes slicing into the fluid and discharging it through the slots 27 or 336 into the surrounding volutes for discharge through the peripheral outlets l4. When the fluid is at a temperature below that which is sufiicient to expand the bimetal elements into their curled vane positions, these elements will close the slots in the rotor peripheries to form shut-elf valves separating the inlets and outlets.

When the pumps of this invention are used as coolant pumps for liquid-cooled engines the pump rotor provides its own thermostat valve between the engine and radiator and the heretofore necessary extra valve is eliminated without loss of function.

If desired, the pump rotor can be arranged So-that'thet" oi-metal elements swing out instead of in, or so that the curling occurs only when temperature drops below a predetermined degree. Thus placement of the most ex pansive metal on the inner wall will cause slot closing movement upon increase in temperature and vane curling movement upon decrease in temperature.

Thus this invention provides a simple, inexpensive, thermo-sensitive centrifugal pump assembly which is eflicient in operation and easily assembled.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a fluid pump including a housing connected to a fluid inlet and outlet, the improvement of an impeller movable within the housing, said impeller having an annular axial portion having circumferentially spaced openings therethrough defining fluid channels in communication with the inlet and the outlet, and bi-metallic elements on said impeller and extending over said channels to define valves for opening and closing the channels in response to variations in fluid temperature, said bi-metallic element being comprised of laminated metal strips with the strip in closest proximity to the channel being of a higher coeflicient of thermal expansion than the other strip.

2. In a fluid pump including a housing connected to a fluid inlet and outlet, the improvement of an impeller movable within the housing, said impeller having at least one radially extending fluid channel in communication with the inlet and the outlet, at least one bi-metallic element on said impeller with the element having a radially deflectable free end extending over said radial channel defining a valve for opening and closing the channel in response to variations in fluid temperature, the free end of said bi-metallic element when in an open position being radially spaced from the radial channel and defining a vane to direct fluid into the channel, and

stop means on said impeller adjacent the channel for limiting the deformation of the heat responsive element.

3. In a fluid pump including a housing connected to a fluid inlet and outlet, the improvement of an impeller movable within the housing, said impeller having at least one opening therein defining a fluid channel in communication with the inlet and the outlet, and at least one.

bi-metallic element on said impeller and extending over said channel to define a valve for opening and closing the channel in response to variations in fluid temperature, said bi-metallic element being comprised of strips secured together with the strip in closest proximity to the channel being of a higher coeflicient of thermal expansion than the other strip and with the other strip being integral with and cut out from the wall of the impeller.

4. An impeller for use in a centrifugal pump having an inlet and outlet including an annular radially extending member having connected thereto an axially extending member, heat responsive valve means on said axially extending member including a channel through said axial member in communication with the inlet and outlet and a bi-metallic element for opening and closing same in response to predetermined variations in fluid temperature, said bi-metallic element when in an open position serving as a vane for facilitating in the pumping of fluid, and stop means on said radially extending member limiting the deformation of the bi-metallic element when in an open position. i

5. A combined pump and thermo-sensitive valve which comprises a casing defining a chamber with a central eye inlet and a peripheral outlet, a rotor in said chamber having a slotted peripheral wall communicating with the inlet on the inside and with the outlet on the outside, and bi-metal elements on said wall closing said slots when below a predetermined temperature tovblock flow from the inlet to the outlet and curling inwardly when heated to form vanes effective to pump fluid from the inside of the wall through the slots for discharge through the outlet.

6. In a fluid displacing structure including fluid inlet and outlet openings, a rotatable impeller having a dished area in communication with one of the fluid inlet and outlet openings with said dished area defined at its radially outer side by an outer annular impeller wall which wall has a series of radially outwardly extending passageways which are in communication with the fluid inlet and outlet openings, and heat responsive shut-off valve means for aiding in the control of the fluid flow through the inlet and outlet openings comprising a series of vanes, said vanes being mounted on the impeller and extending into the dished area in proximity to the passageways.

7. In a fluid pump including a housing connected to a fluid inlet and outlet, the improvement of an impeller movable within the housing, said impeller having a series of openings therein defining fluid channels in communication with the inlet and the outlet, and bi-metallic elements on said impeller each extending over one of said channels to define a valve for opening and closing the channel in response to variations in fluid temperature, said bi-metallic element when in an open position being turned to define a vane to direct fluid into the channel.

8. In a fluid pump including a housing connected to a fluid inlet and outlet, the improvement of a rotatable member movable within the housing with the rotatable member having a series of passageways therein defining radial fluid channels in communication with the inlet and the outlet, and circumferentially spaced bi-metallic elements on said rotatable member and extending across said channels to define shut-ofl thermostatic valves for opening and closing the channels in response to variations in fluid temperatur 9. A dished type impeller for use in a centrifugal pump having an inlet and outlet including an annular radially extending portion and an axially extending portion connected thereto together defining the dish and with the radially extending portion disposed radially inwardly of the axially extending portion, the axially extending portion havingradial channels, and heat responsive valve means comprising laminated bi-metallic vanes on said axially extending portion extending over the radial channels in communication with the inlet and outlet, said heat responsive valve means in an open position being bent and deflected radially away from the radial channels and in a bent position comprising a vane for facilitating in the pumping of fluid.

10. In a centrifugal pump having an inlet and outlet, an impeller including an annular radially extending portion and an axially extending peripheral flange having ports connecting the inlet and outlet, and heat responsive valve means on the radially inner side of said axially extending flange, including bi-metallic elements for opening and closing the ports in response to predetermined variations in fluid temperature, said bi-metallic elements comprised of metal strips of dilferent coetficients of expansion with the radially inner strip having the lower coeflicient of expansion thereby permitting the other strip in response to increased fluid temperatures to curl the elements away from the ports to open the ports.

References Cited in the file of this patent UNITED STATES PATENTS 1,015,552 Gamon Jan. 23, 1912 2,005,193 Mayo June 18, 1935 2,114,567 Mercur Apr. 19, 1938 2,292,082 Miller Aug. 4, 1942 2,295,944 Fitzsimmons Sept. 15, 1942 2,385,096 McCollum Sept. 18, 1945 

